Very low transfer speed for ESP32-C6 with ESP_HOSTED_FG

Checklist

[X] Checked the issue tracker for similar issues to ensure this is not a duplicate
[X] Read the documentation to confirm the issue is not addressed there and your configuration is set correctly
[X] Tested with the latest version to ensure the issue hasn't been fixed

How often does this bug occurs?

always

Expected behavior

I am currently set the ESP32-C6 to SDIO mode with low SDIO frequency (20Mhz), the module is an official ESP32-C6-MINI1 on a custom board with a Linux host. The kernel version of the linux is too old to use the ESP_HOSTED_NG.

Actual behavior (suspected bug)

We are happly about everything ESP_HOSTED_FG provided, but the transfer speed is very slow. We were expecting something aroung 10Mbps, but it only runs to ~2Mhz unidirectional, no matter TCP or UDP, send or receive.

esp32-c6 startup:

wifi signal strength:

iperf result:

Error logs or terminal output

No response

Steps to reproduce the behavior

Build with main branch and IDF. Commit: ce00ca53189ffd52455dd5426d54f9be6fae1871

Project release version

FG-0.0.6.0.0

System architecture

other (details in Additional context)

Operating system

Linux

Operating system version

Cortex-A7, Custom rootfs and kernel, Linux Kernel 3.10.0

Shell

Bash

Additional context

ESP_IDF Config: https://gist.github.com/MarsTechHAN/e47461dd75386a06eedb0de12c2c6251

espressif / esp-hosted